The present invention relates to a computer system.
An increased demand for the SoE (system of engagement) IT structure requires an IT structure to have agility, scalability, and high cost effectiveness.
For example, a hyper-converged system can start from a small-scale server structure, and can be expanded to a large-scale server. For this reason, the hyper-converged system is increasing its market share as a product targeted for the private cloud. A hyper-converged system includes a plurality of server nodes each of which has a local storage. Each server node has a virtualization function and storage function, and duplicates data by communicating with each other via a network
U.S. Pat. No. 8,601,473 discloses an example of the hyper-converged system. The following is disclosed in U.S. Pat. No. 8,601,473, for example. “Disclosed is an improved approach to implement I/O and storage device management in a virtualization environment. According to some approaches, a Service VM is employed to control and manage any type of storage device, including directly attached storage in addition to networked and cloud storage. The Service VM implements the Storage Controller logic in the user space, and can be migrated as needed from one node to another. IP-based requests are used to send I/O request to the Service VMs. The Service VM can directly implement storage and I/O optimizations within the direct data access path, without the need for add-on products.” (Abstract)
On the other hand, due to a strong demand for IoT and data analysis, a system using a flash drive has a greater share in the market. A flash drive has a life that depends on the number of times data was written. As a greater number of flash drives have multi-cells to achieve a larger capacity and lower price, the allowable number of writing has been reduced.